[analyzer] Do not walk the types for call graph construction.

Similar to r156661. This should be beneficial performance wise and
hopefully, resolve a RecursiveASTVisitor crash that we are seeing in the
wild, but are incapable of reproducing.

llvm-svn: 158851

clang/include/clang/Analysis/CallGraph.h

@@ -121,6 +121,8 @@ public:
     return true;
   }
 
+  bool shouldWalkTypesOfTypeLocs() const { return false; }
+
 private:
   /// \brief Add the given declaration to the call graph.
   void addNodeForDecl(Decl *D, bool IsGlobal);